Buenos Aires: Doctors treating the pregnant girlfriend of Argentine football icon Lionel Messi for a urinary infection have said Antonella Roccuzzo is stable and that the illness poses no threat to her pregnancy.

Roccuzzo, 27, had a "good night" and her condition is improving, according to the latest bulletin released on Wednesday by Hospital Español in the FC Barcelona star's native city of Rosario, reports Efe.

"She will remain hospitalised with the treatment initiated 24 hours ago, with continuous monitoring. Both the patient and the pregnancy remain stable," Dr. Jose Gentillini said.

Roccuzzo entered the hospital on Tuesday morning.

"It's fine, luckily the hardest part has passed," Messi told reporters as he left the hospital on Tuesday night.

Messi, Roccuzzo and the couple's two-year-old son, Thiago, were taking a brief vacation in Arroyo Seco, near Rosario, after the the 28-year-old, regarded by many as the world's best footballer, joined the Argentine national team for the Copa America tournament in Chile.